fix: Increase folder link field size (#26381) (#26383)

* fix: increase folder length to 255

File `name` is 255 because it's bootstrapped using mariadb.sql, so users
can create 255 char long folders but can't store anything in it.

* fix(UX): slightly better character len message

Highlight field by making it bold.

(cherry picked from commit 5351763)

# Conflicts:
#	frappe/core/doctype/file/file.json
#	frappe/model/base_document.py

Co-authored-by: Ankush Menat <ankush@frappe.io>

frappe/core/doctype/file/file.json

@@ -106,6 +106,7 @@
    "fieldtype": "Link",
    "hidden": 1,
    "label": "Folder",
+   "length": 255,
    "options": "File",
    "read_only": 1
   },
@@ -188,7 +189,7 @@
  "icon": "fa fa-file",
  "idx": 1,
  "links": [],
- "modified": "2023-07-26 14:03:49.456951",
+ "modified": "2024-05-09 11:46:42.917146",
  "modified_by": "Administrator",
  "module": "Core",
  "name": "File",
@@ -220,4 +221,4 @@
  "states": [],
  "title_field": "file_name",
  "track_changes": 1
-}
+}

frappe/model/base_document.py

@@ -969,7 +969,7 @@ def throw_length_exceeded_error(self, df, max_length, value):
 
 		frappe.throw(
 			_("{0}: '{1}' ({3}) will get truncated, as max characters allowed is {2}").format(
-				reference, _(df.label), max_length, value
+				reference, frappe.bold(_(df.label)), max_length, value
 			),
 			frappe.CharacterLengthExceededError,
 			title=_("Value too big"),